Cold regions hydrology is undergoing rapid transformation due to climate warming, permafrost thaw, shifting precipitation regimes, and evolving cryospheric processes. These changes have profound implications for water availability, water quality, ecosystem health, and community well-being across high-latitude and alpine environments. This session brings together field observations, modeling studies, isotopic and geochemical tracers, and community-based research to advance our understanding of hydrological processes in cold regions. We particularly encourage contributions that examine surface–groundwater interactions, snow and glacier hydrology, evapotranspiration and vegetation dynamics, and long-term water balance assessments.